Pump



D. MURPHY Oct. 20, 1953 PUMP 2 Sheets-Sheet 1 Filed May 9, 1947 IN VENT OR.

Daniel Murphy ATTORNEYS Oct. 20, 1953 D. MURPHY 2,655,369

PUMP

Filed May 9, 1947 2 Sheets-Sheet 2 INVENTOR. Daniel Murphy ATTORNEYS Patented Oct. 20, 1953 UNITED STATES PATENT OFFICE PUlVlP Daniel Murphy, New Castle, Pa.

Application May 9, 1947, Serial No. 746,909

9 Claims. 1

My invention relates to centrifugal pumps, particularly, though not exclusively, to self-priming pumps of the type disclosed in Letters Patent No. 2,179,858, granted to me on November 14, 1939.

In the construction and operation of rotary pumps the provision and maintenance of effective bearings and seals for the impeller shafts have constituted an ever present problem. This has been particularly true in those industrial fields wherein the pumps are required to propel liquids containing abrasive material, such liquids as slip used in the pottery industry, or a vitreous enamel carried in a liquid vehicle, or mine water, or other liquids or sludges that carry particulate solid matter that acts with abrading effect upon the seals and bearings of a rotary pump.

In an application for Letters Patent. Serial No. 640,911, filed by me January 12, 1946, and now Patent No. 2,628,745 of February 1'7, 1953, I illustrate and describe an improved rotary pump affording a solution of this problem for a special condition of service. In this pump the impeller chamber is arranged below the surface of the body of liquid that supplies the pump with the liquid to be propelled. The impeller shaft extends from above the surface of the supply body of liquid vertically downward through the liquid and through the upper wall of the impeller cham her, and engages and supports the impeller in said chamber. The bearings and drive for the impeller shaft are all organized above the surface of the liquid, where they are not exposed to the corrosive action of the liquid, nor to the erosive action of solid particles in the liquid. The inlet of the pump comprises the opening in the Wall of the impeller chamber, through which the impeller drive shaft extends; that is to say, the opening in the impeller wall is of substantially larger diameter than the body of the drive shaft that extends therethrough, and the annular space thus provided between the body of the shaft and the periphery of said opening forms the inlet of the pump. The need for packings or seals between the shaft and the wall of the impeller chamber is absolutely dispensed with, and the problem of wear and failure of seals and packings, as well as of the bearing for the drive shaft, is avoided.

My present invention consists in the provision of certain new and useful improvements in pump construction whereby the same advantages may be enjoyed in a rotary pump that is not necessarily located below the surface of the body of liquid which feeds the pump. The pump of my present invention may be a lift pump, that is,

a pump arranged above the surface of the liquid to be pumped, and the need of seals for the drive shaft of the pump is eliminated, and all danger of erosion of the drive-shaft bearings is avoided. These and other advantages and objects of my present invention will be understood upon reference to the accompanying drawings, in which:

Fig. 1 is a view in perspective of a pump embodying in exemplary way the improvements of the invention;

Fig. 2 is a view to larger scale, showing partly in elevation and partly in vertical section the improved pump structure;

Fig. 3 is a fragmentary view, showing certain modifications in the structure of the pump body and of the impeller; and

Fig. 4 is a fragmentary view showing still other modifications in the latter portions of the pump structure.

The pump of the invention is in this case shown with its drive shaft 2 arranged in perpendicular position, rather than in inclined or horizontal position. The pump body 3 includes a main impeller chamber 4 in a pump body portion 5. and an auxiliary impeller chamber '6 in a pump body portion 1, the two impeller chambers being separated by a partition 50 integral with the pump body portion 5. Preferably, an overflow pan 8 is provided, and to the flanged opening 9 in the bottom of this pan the assembled pump body is bolted. The pan 8 is formed of sturdy cast iron or steel, mounted upon steel legs l0, and as thus constructed provides the base or support for the pump asembly, which includes an electric motor I l, a bearing bracket I 2 having antifriction bearings I3 and It for the pump drive shaft 2. and a pulley-and-belt drive I5 connecting the motor to said drive shaft.

The drive shaft extends downwardly through the opening 9 in the bottom of pan 8, and through an opening it in upper wall of the auxiliary impeller chamber 6, and through an-opening I! in the partition 59 that forms the top wall of the mainimpeller chamber 4. Upon the lower and otherwise free end of the shaft a vaned impeller l8 is secured. The impeller may be of the type disclosed in Letters Patent No. 2,128,496, granted to me August 30, 1938, consisting of a plate-like body having curved radial vanes on its under side adapted to cooperate with a Wearing plate [9 adjustably secured, as by screws 20, to the pump body portion 5 and comprising the bottom wall of the chamber A. An inlet orifice is provided in the center of the wearing plate or wall [9, and advantageously such inlet orifice is provided with a downwardly extending tube 2| that terminates above the bottom of a well 22 formed in pump body portion 23 assembled upon body portion 5. When the motor H is energized and powerfully rotates the shaft 2, the rotated impeller l3 operates in known way to exert a suction in the inlet orifice in plate or wall l9, and under the effect of such suction the liquid to be pumped is drawn upward, through a pipe 24, a check valve 25, an intake passage 23, the well 22, and tube 2 I, into the passages between the blades or vanes of the rotating impeller, whence, under centrifugal force, the liquid is expelled into the impeller chamber 4. From chamber 4 a tangential outlet passage opens through a tubular portion 21 of the pump body, and through this passage the liquid is delivered from the impeller chamber into a duct 28 leading to a discharge or priming chamber 29 that opens through a check valve 33 to the discharge line 31, leading to the desired ultimate point of delivery.

It is important to note that the opening I! through which the shaft 2 makes engagement with the impeller H3 in the main pump chamber 4 is of such size as to eliminate any danger of frictional wear or engagement between the rotating parts and the wall 50 in which the opening is formed. A one-quarter inch clearance is provided between the shaft 2 and the edge of the opening H in the pump herein shown. Heretofore, sealing devices or packings have been provided on pump drive shafts adjacent to the points where the shafts extend through the wall of the impeller chambers, to prevent the escape of liquid under pump delivery pressure from such chambers. As distinguished from such practice, I provide means which eliminate the need for packings or sealing devices. Such leakage as may occur through the clearance I1 is received into the auxiliary impeller chamber 6, which is, as shown in this case, arranged in close juxtaposition with respect to the main pumping chamber 4, and communicates therewith through the clearance H. In this auxiliary chamber an impeller is rotated to deliver the leakage liquid to the dis- .5

charge line of the pump. Where, as here, the auxiliary chamber is arranged adjacent to the main pump chamber, the impeller 32 in the auxiliary chamber is mounted on the same drive shaft 2 that supports and drives the main impeller 18. The impeller vanes on the auxiliary impeller are directed upward, and cooperate with a, wearing plate 33 press-fitted in the wall of pump body portion 7, and it will be understood that the vanes of the auxiliary impeller are of opposite hand to the vanes on the main impeller, so that the rotation of the two impellers in the same direction will result in each producing the desired pumping action. The liquid which leaks from the main pumping chamber 4 enters the auxiliary chamber 6, whence it is delivered under the propulsion of the impeller 32 through the outlet 34 of the auxiliary pump chamber, and thence through a check valve 35 and auxiliary discharge line 36 to the discharge or priming chamber 29. The check valve 35 is similar in structure to the check valves 25 and 30 illustrated in the drawings.

Seals and packing glands are also avoided in the case of the auxiliary pumping chamber, by providing the opening [6 of larger size than the drive shaft that extends through it, the clearance being in the order of one-half inch in the pump illustrated. Through this clearance air enters from open passage 9 while the pump is in opera- 1 remains in the pump body beneath the lower wall (I9) of the main pump chamber, ready to initiate flow when the pump is again started. Even though the check valve should develop a leak and permit liquid to seep back to the source, there would nonetheless be an adequate store of liquid retained in the well 22 for starting. The liquid in the discharge chamber 29 provides, when the pump is shut down, a store of priming liquid for the main pump impeller. This liquid may settle under gravity through passages 28 and 21 into the main pump chamber 4, and keep such chamber filled, ready for instant operation, it being noted that the check valve opens as the liquid level in chamber 29 lowers, to permit air to enter through clearance [6, pump chamber 6, outlet passage 34, check valve 35 and auxiliary discharge line 33, into said priming chamber 29.

In the event that any of the check valves on the discharge side of the pump does not operate satisfactorily, or if for any other reason there is a back surge of liquid into and through the pump chambers i and 6, such back flow of liquid rises into the pan 8, and is discharged through an outlet pipe 37, leading back to the source of the liquid to be pumped, or to a drain or other place of disposal.

The arrangement of two impellers of opposite hand" upon the end of the drive shaft 2 is effective substantially to neutralize end thrust acting upon the shaft as the result of the reaction of the impeller upon the liquid being pumped. In consequence of this neutralization of end thrust the wear upon the bearings is minimized, and the tendency toward the shaft to whip is eliminated; that is, the neutralization of end thrust cooperates with the tapered form of the lower end of the shaft in the prevention of the whipping of the shaft during pump operation.

It will be noted that the pump as illustrated and described is arranged above the source of liquid to be pumped. It is possible, however, to arrange the pump below the source of the liquid to be pumped, and in such case a check valve will be arranged in the inlet line of the pump, say an electrically operated check valve (not shown) which will close automatically when the operation of the pump is arrested, thereby preventing the overflow of liquid under gravity through the pump and into the pan 8. This electrically operated check valve will be substituted for the check valve 25 shown in the drawings.

Whereas in Fig. 2 two individual impellers are mounted upon the drive shaft, it is to be understood that, in modification, the two impeller structures may be incorporated in a single unit and mounted upon the shaft as shown at 64 in Fig. 3. In such case the partition a between the two impeller chambers 40, and 611 may include an opening Ila of a diameter slightly larger than the diameter of the impeller, and through this opening or clearance Ha. the liquid escaping from the lower impeller chamber M will enter the upper impeller chamber 6a, whence it will be dc accaeco livered through the auxiliary discharge line 35 (Fig. 2) to the discharge chamber 29. In still further modification, as shown in Fig. 4, the partition 502;- between the impeller chambers 4b and 66 may be formed integrally upon the double impeller 64b, in such manner that the clearance, through which the two impeller chambers com-- municate, is provided at the outer peripheral edge of the impeller, as shown at Hb in Fig. 4.

Still other modifications are held in contemplation within the spirit of the invention defined in the appended claims.

I claim:

1. A pump comprising a pump body including an impeller chamber having an inlet passage and an outlet, a rotary impeller in said chamber for propelling liquid, 9. drive shaft extending downwardly from above said chamber and engaging said impeller through an opening in the wall of said chamber and rotatably supporting the impeller in said chamber, with a peripheral space between the shaft and the periphery of said opening, bearing means for said shaft, the bearing means for said shaft being mounted above said opening and out of contact with the liquid being propelled, a delivery line extending from said outlet to an elevation above said impeller chamber, means including an outlet passage for discharging into said delivery line, at a point above said impeller chamber, the liquid leaking through said peripheral space from said impeller chamber when the pump is in operation, and a check valve in said outlet passage adapted to close against backfiow in said outlet passage and to open when there is backflow from said delivery line to said impeller chamber.

2. A pump comprising a pump body including an impeller chamber having an inlet passage and an outlet, a rotary impeller in said chamber for propelling liquid, a drive shaft extending downwardly from above said chamber and engaging said impeller through an opening in the wall of said chamber and rotatably supporting the impeller in said chamber, with a peripheral space between the shaft and the periphery of said opening, bearing means for said shaft, the bearing means for said shaft being mounted above said opening and out of contact with the liquid being propelled, a delivery line, a priming chamber arranged above said impeller chamber and in communication with said delivery line, means including an outlet passage communicating with said priming chamber for discharging the liquid leaking through said peripheral space from said impeller chamber when the pump is in operation, and a check valve in said outlet passage adapted to close against backfiow in the outlet passage and to open when there is b-ackfiow from said delivery line to said impeller chamber.

3. A pump comprising a pump body includin an impeller chamber having an inlet and an outlet, a rotary pump impeller in said chamber for propelling liquid, a drive shaft extending downwardly from above said chamber and engaging said impeller through an opening in the wall of said chamber and rotatably supporting the impeller in said chamber, with a peripheral space between" the shaft and the periphery of said opening, bearing means for said shaft, the bearing means for said shaft being mounted above said opening and out of contact with the liquid bein propelled, an auxiliary impeller chamber having an outlet and including a passage in its wall through which said shaft extends, said peripheral space in the wall of said first impeller chamber communicating with said auxiliary impeller chamber, an auxiliary pump impeller mounted on said shaft in said last chamber for delivering through said auxiliary chamber outlet the liquid leaking from the first impeller chamber through said peripheral space, and'means connecting the outlets of both of said impeller chambers to a common delivery line, and a check valve in the outlet passage of said auxiliary impeller chamber adapted to close against backflow in such passage.

4. A pump comprising a pump body including an impeller chamber having an inlet and an outlet, a rotary pump impeller in said chamber for propelling liquid, a drive shaft extending downwardly from above said chamber and engaging said impeller through an opening in the wall of said chamber and rotatably supporting the impeller in said chamber, with a peripheral space between the shaft and the periphery of said opening, bearing means for said shaft, the hear-- ing means for said shaft being mounted above said opening and out of contact with the liquid loeing propelled, an auxiliary impeller chamber having an outlet and including a passage in its wall through which said shaft extends, said clearance in the wall of said first impeller cham-- ber communicating with said auxiliary impeller chamber, an auxiliary pump impeller mounted on said shaft in said last chamber for delivering through said auxiliary chamber outlet the liquid leaking from the first impeller chamber through said clearance, and means connecting the outlets of both of said impeller chambers to a common delivery line, together with a check valve in the line of flow from the outlet of said auxiliary im'- peller chamber, said check valve being adapted to close against backfiow into the latter outlet and to open when there is backflow in the outlet of the first impeller chamber.

5. A pump comprising a pump body including an impeller chamber having an inlet and an outlet, a rotary pump impeller in said chamber for propelling liquid, a drive shaft extending downwardly from above said chamber and engaging .said impeller through an openin in the wall of said chamber and rotatably supportingthe impeller in said chamber, with a peripheral space between the shaft and the periphery of said opening, bearing means for said shaft, the bearing means for said shaft being mounted above said opening and out of contact with the liquid being propelled, an auxiliary impeller chamber having an outlet and including a passage in its wall through which said shaft extends, said peripheral space in the wall of said first impeller chamber communicating with said auxiliary impeller chamber, an auxiliary pump impeller mounted on said shaft in said last chamber for pumping into said auxiliary chamber outlet liquid leaking from the first impeller chamber through said peripheral space, and a delivery line extending above both of the said impeller chambers, with passages connecting the outlets of both chambers connected to such line, and a check valve in at least one of the latter passages.

6. A rotary pump having a pump body including an impeller chamber, a pump impeller in said chamber, an inlet leading into said chamber and an outlet leading from said chamber for the fluid to be pumped, the wall of said chamber including a free opening, a rotary drive shaft engaging said impeller through said opening, a second impeller chamber, said second impeller chamber standing in direct communication with said opening, an outlet leading from said second chamber, and a pump impeller rotatably mounted in said second chamber for pumpin fluid escaping from the first chamber through said opening, both of said pump impellers having delivery passages arranged to deliver liquid through said outlets into a common delivery line, and a check valve in one of said delivery passages.

7. A rotary pump having a pump body including an impeller chamber, a pump impeller in said chamber, an inlet leading into said chamber and an outlet leading from said chamber for the fluid to be pumped, the wall of said chamber including a free opening, a rotary drive shaft engaging said impeller through said opening, a second impeller chamber, said second impeller chamber standing in direct communication with said opening, an outlet leading from said second chamber, and a pump impeller rotatably mounted in said second chamber for pumping fluid escaping from the first chamber through said opening, a delivery line into which said outlets open, and a priming chamber arranged in said delivery line, the outlet from said first impeller chamber communicating with said priming chamber at a point below that at which said second impeller chamber cjommunicates therewith, and a check valve in the line of communication between the second impeller chamber and the said priming chamber.

8. A pump comprising a pump body including an impeller chamber having an inlet and an outlet, a rotary pum impeller in said chamber for propelling liquid, a drive shaft extending downwardly from above said chamber and engaging said impeller through an opening in the wall of the chamber and rotatably supporting the im peller in said chamber, with a peripheral space between the shaft and the periphery of said opening, bearing means for said shaft, the hearing means for said shaft being mounted above said opening and out of contact with the liquid being propelled, an auxiliary impeller chamber having an outlet and including a passage in its wall through which said shaft extends, said peripheral space in the wall of said first impeller chamber communicating with said auxiliary impeller chamber, an auxiliary pump impeller mounted on said shaft in said last chamber for pumping into said auxiliary chamber outlet liquid leaking from the first impeller chamber through said peripheral space, a delivery line extending above both of said impeller chambers, with passages connecting the outlets of both chambers to such line, a check valve in at least one of the latter passages, and a peripheral space, between said shaft and the passage in the wall of said auxiliary chamber, standing in open communication between the atmosphere externally of said impeller chambers and the" suction-producing body portion of said auxiliary impeller.

9. A pump comprising a pump body including an impeller chamber having an inlet and an outlet, a rotary pump impeller in said chamber for propelling liquid, a drive shaft extending downwardly from above said chamber and engaging said impeller through an opening in the wall of said chamber and rotatably supporting the impeller in said chamber, with a peripheral space between the shaft and the periphery of said opening, bearing means for said shaft, the bearing means for said shaft being mounted above said opening and out of contact with the liquid being propelled, an auxiliary impeller chamber having an outlet and including a passage in its wall through which said shaft extends, said peripheral space in the wall of said first impeller chamber communicating with said auxiliary impeller chamber, an auxiliary pump impeller mounted on said shaft in said last chambers for pumping into said auxiliary chamber outlet liquid leaking from the first impeller chamber through said peripheral space, a delivery line extending above both of said impeller chambers, with passages connecting the outlets of both chambers to such line, a check valve in at least one of the latter passages, and a peripheral space, between said shaft and the passage in the wall of said auxiliary chamber, standing in open communication between the atmosphere externally of said impeller chambers and the suction-producing body portion of said auxiliary impeller, together with an overhead drainage receptacle for liquid communicating with said last peripheral space.

DANIEL MURPHY,

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 976,340 Blair Nov. 22, 1910 1,472,560 Grifiiths et al. Oct; 30, 1923 1,480,436 Grifiin Jan. 8, 1924 7 1,556,657 Wilfley Oct. 13, 1925 1,321,772 Ruthman Sept. 1, 1931 2,046,904 Morgan July 7, 1936 2,166,530 Morgan July 18, 1939 2,179,730 Ruthman Nov. 14, 1939 2,250,714 La Bour July 29, 1941 2,292,529 La Bour Aug. 11, 1942 2,297,001 La Bour Sept. 29, 1942 2,381,823 La Bour Aug. 7, 1945 FOREIGN PATENTS Number Country Date.

378,091 Germany July 10, 1923 517,824 Germany Feb, 7, 1931 652,168 Germany Oct. 26, 1937 

